Synthetic studies on the cornexistins: synthesis of (+/-)-5-epi-hydroxycornexistin.
The synthesis of 5-epi-hydroxycornexistin (44), a diastereoisomer of the herbicidal natural product hydroxycornexistin (2) has been completed. Palladium mediated sp(2)-sp(3) coupling of the stannane 25 and the chloride 31 and ring-closing metathesis of the resulting diene 32 has been used to construct the tricyclic lactone 34a, which possesses the nine-membered carbocyclic core found in the natural product, in good yield. The synthesis of 5-epi-hydroxycornexistin (44) has established the feasibility of using a furan as precursor for the cyclic anhydride unit present in the natural product and has demonstrated the viability of other late-stage transformations that will be used to prepare hydroxycornexistin (2).
Clark
J Stephen
JS
WestCHEM, Department of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK. stephenc@chem.gla.ac.uk
Northall
John M
JM
Marlin
Frédéric
F
Nay
Bastien
B
Wilson
Claire
C
Blake
Alexander J
AJ
Waring
Michael J
MJ
D000475:Alkenes / Q000737:chemistry; D018360:Crystallography, X-Ray; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D009579:Nitrobenzoates / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D013237:Stereoisomerism
C533507:5-epi-hydroxycornexistin; D000475:Alkenes; D005663:Furans; D006575:Heterocyclic Compounds, 3-Ring; D007783:Lactones; D009579:Nitrobenzoates; C071795:cornexistin; C008629:4-nitrobenzoic acid; D012825:Silicon